Antenna Application in Wireless Earphones

ABSTRACT

A wireless earphone incorporates a wire antenna having a form factor driven innovative antenna shape that minimizes antenna detuning caused by user interactions with the earphones. The wire shape, diameter, and distance of the wire antenna from the printed circuit board (PCB) are selected for an acceptable tradeoff between antenna bandwidth and radiated efficiency. By inserting an end through a through-hole of the PCB, the wire antenna is electrically connected to a multi-layer PCB without traditional approaches such as springs, pogo pins, and the like. An antenna holder further secures the antenna within a thin profile housing for precise placement and manufacturing consistency. A PCB-specific RF VIA geometry is also utilized for partial impedance matching of a transmission line to the wire antenna. In addition, a more constant impedance is maintained along the transmission line connecting a radio device with the wire antenna.

This application claims priority to provisional Application No.63/038,972 filed Jun. 15, 2020, which is incorporated by reference inits entirety herein.

TECHNICAL FIELD

One or more aspects of the disclosure generally relate to an antennaapplication in wireless earphones. The wireless earphones may operate ata desired frequency spectrum, for example, Bluetooth frequency range(approximately 2.402 GHz to 2.480 GHz).

BACKGROUND

Unlike a traditional wired earphone, wireless earphones provide anuntethered connection to a paired content source. Consequently, usermovement is constrained only by the bounds of a communication channelbetween the wireless earphone and the content source. In addition,wireless earphones are typically situated close to a user's body sincethe wireless earphones operate near, on, or within the user's ears. Forexample, wireless earphone operating within the Bluetooth spectrum(approximately 2.40-2.48 GHz) may incur transmission degradation when auser places his/her hand near the wireless earphones because theelectrical permittivity of the human body is very high. This degradationoften results in received signal dropping and the extracted audiocontent being disrupted.

In light of the above observations, the performance of wirelessearphones may be enhanced with respect to traditional approaches byimproving the robustness of the communication channel between thewireless earphones and the paired communication device.

SUMMARY

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the disclosure.

A wireless earphone incorporates a wire antenna having a form factordriven innovative antenna shape that minimizes antenna detuning causedby user interactions with earphones. The wire shape, diameter, anddistance of the wire antenna attached to the printed circuit board (PCB)are optimized for a desired tradeoff between antenna bandwidth andradiated efficiency.

With another aspect of the disclosure, a wire antenna is electricallyconnected to a multi-layer PCB without traditional approaches such assprings, pogo pins, and the like. The electrical connection is reliableand low cost while supporting a PCB specific RF VIA geometry that can beutilized for partial impedance matching of the wireless earphones to theantenna.

With another aspect of the disclosure, an antenna holder providesprecise placement of a wire antenna with respect to a PCB andcorresponding electrical components for precise placement andmanufacturing consistency important to antenna performance. High antennaperformance results in a robust communication channel between wirelessearphones and the paired device. Moreover, dielectric material may beselectively removed from the antenna holder to reduce dielectric lossesin the wire antenna.

With another aspect of the disclosure, a wireless earphone includes amulti-layer printed circuit board (PCB) having a plurality of PCBlayers, an antenna assembly comprising a wire antenna, and an impedancematching interface. The wire antenna has an end inserted through athrough-hole of the multi-layer PCB and is electrically connected to topand bottom pads. The wireless earphone is partially matched to theantenna impedance by an electrical interaction between the end of thewire antenna and the plurality of PCB layers.

With another aspect of the disclosure, an impedance matching interfacecomprises a shunt capacitor, where the wireless earphone is furthermatched to the antenna impedance by the shunt capacitor.

With another aspect of the disclosure, a wireless earphone includes amicrostrip (transmission line) that electrically connects a radio deviceto a wire antenna via an impedance matching interface. An electricalcomponent (for example, a surface mounted filtering device) that has acorresponding pad is often located along the microstrip. Because thecorresponding pad may be wider than that of the microstrip, thecharacteristic impedance along the microstrip changes. In order tomitigate the impedance change, at least a portion of the ground planebelow the electrical component on the adjacent PCB layer may be cut out.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the exemplary embodiments of thepresent invention and the advantages thereof may be acquired byreferring to the following description in consideration of theaccompanying drawings, in which like reference numbers indicate likefeatures and wherein:

FIG. 1 shows a wireless earphone worn by a user in accordance with anaspect of the embodiments.

FIG. 2 shows components of a wireless earphone that support acommunication channel between the wireless earphone and a paired devicein accordance with an aspect of the embodiments.

FIG. 3 shows a view of a printed circuit board (PCB) of a wirelessearphone in accordance with an aspect of the embodiments.

FIG. 4 shows a cross sectional view of a wire antenna incorporated in awireless earphone in accordance with an aspect of the embodiments.

FIG. 5 shows a side view of a wireless earphone in accordance with anaspect of the embodiments.

FIG. 6 shows a wire antenna mounted at a PCB through-hole of a wirelessearphone in accordance with an aspect of the embodiments.

FIG. 7 shows a PCB layer specific VIA PCB stack-up geometry providingpartial impedance matching to a wire antenna in accordance with anaspect of the embodiments.

FIG. 8 shows a wire antenna positioned by an antenna holder inaccordance with an aspect of the embodiments.

FIG. 9 shows a part of transmission line (microstrip) located on a PCBof a wireless earphone in accordance with an aspect of the embodiments.

FIG. 10 shows a portion of a transmission line of a wireless earphone inaccordance with an aspect of the embodiments.

FIG. 11 shows a process for implementing a wireless earphone inaccordance with an aspect of the embodiments.

FIG. 12 shows a wireless earphone worn by a user in accordance with anaspect of the embodiments.

FIG. 13 shows a wire antenna positioned by an antenna holder inaccordance with an aspect of the embodiments.

FIGS. 14-15 show aspects of the disclosure in which the effects of userinteraction upon antenna detuning are reduced.

DETAILED DESCRIPTION

In the following description of the various exemplary embodiments,reference is made to the accompanying drawings which form a part hereof,and in which is shown by way of illustration various embodiments inwhich the invention may be practiced. It is to be understood that otherembodiments may be utilized and structural and functional modificationsmay be made without departing from the scope of the present invention.

Aspects of the embodiments are directed to a wireless earphoneinteracting with a content source (paired device) over a one-way orbi-directional communication channel. Embodiments may support differenttypes of paired devices, including but not limited to, smart phones,media players, car radios, and the like. Moreover, embodiments maysupport Bluetooth operation that typically utilize frequencies between2.400 to 2.4835 GHz. However, embodiments may support other wirelessservices that operate in conjunction with and the Internet of Things(IoT) utilizing different wireless spectra.

With traditional approaches, earphones utilizing Bluetooth operationoften encounter degraded operation resulting from its electricalcharacteristics being affected by a user's proximity. Degraded operationof the communication channel may cause the wireless signal to bedisrupted, resulting in content at the wireless earphone being lost.Referring to FIG. 1, wireless earphones 101 are typically close to theuser's body since the earphones are worn near, on, or in the user's ear102. For example, when the user moves his/her hand near earphones 101,the performance of an internal antenna (not explicitly shown) may beadversely affected since a human body is characterized a high electricalpermittivity (typically 40-60). In general, any human body part shouldstay away from the antenna. As will be discussed, aspects of theembodiments address this concern.

FIG. 2 shows components of a wireless earphone that support acommunication channel between wireless earphone 101 and a paired device(not explicitly shown) in accordance with an aspect of the embodiments.Embodiments may support a bi-directional (two-way) channel or a one-way(from paired device to wireless earphone 101).

With some embodiments, earphone 101 comprises radio device 201,transmission line (microstrip) 202, impedance matching interface 203,and antenna assembly 204.

Radio device 201 (which may comprise an RF transceiver or only areceiver) processes a received wireless signal obtained from antennaassembly 204 through RF matching network 205, band pass filter (BPF)206, and transmission line 202. Radio device 201 is often designed tooperate at an impedance of 50 ohms; however, antenna assembly 204 ischaracterized by an antenna impedance different from 50 ohms.Consequently, impedance matching interface 203 more closely matchesantenna assembly 204 with radio device 201. Impedance matching interface203 will be discussed in greater detail with FIG. 7.

When radio device 201 comprises a wireless transceiver, a wirelesssignal may be generated to support a communication in the reversedirection from wireless earphone 101 to the paired device. For example,an acknowledgement (ACK) or configuration information may be sent to thepair device to control the content flow to wireless earphone 101.

Earphone 101 sends and/or receives a wireless signal at antenna assembly204. As will be discussed, antenna 204 may comprise a wire antenna (forexample 301 as shown in FIG. 8) that is held in place by antenna holder801.

FIG. 3 shows view 300 of a printed circuit board (PCB) of wirelessearphone 101 in accordance with an aspect of the embodiments. As shownin FIG. 1, earphone 101 is typically worn by a user, where button 303 isin the upward direction. The user can then depress button 303 pushing itwith one finger and supporting the bottom of earphone 101 with the thumb(for example at region 306), which does not significantly degrade theperformance of wire antenna 301.

With some embodiments, as shown in FIG. 3, wire antenna 301 incorporatesan innovative antenna shape that minimizes antenna detuning caused byuser interactions with the earphones. Antenna 301 has a wire lengthrequired for proper resonance at the approximate center frequency of thedesired spectrum, where the length is slightly longer than a quarterwavelength. For Bluetooth operation, the center frequency isapproximately 2.44 GHz.

Because antenna 301 is constrained to be located within a thin-profilehousing of wireless earphone 101, antenna 301 is bent to beapproximately parallel to the PCB and shaped to curve around the rightside of housing 305. Antenna 301 is also shaped to reduce the effects ofhuman finger loading and detuning effects. Consequently, antenna end 304is sharply bent to avoid being too close to battery 302 as well as theuser's thumb that may be positioned at the bottom. Battery 302 is oftenthe electrical component most adversely affecting antenna 301 (forexample, detuning and antenna radiated efficiency loss) because it isrelatively large and metallic.

The height of battery 302 is typically comparable to the height ofantenna 301, and consequently battery 302 may have a profound effectupon the performance of antenna 301. With traditional approaches,battery 302 is a part of RF ground at the operational frequency. With anaspect of the embodiments, the adverse effect of battery 302 isameliorated by floating battery 302 at the antenna operating frequency.This may be achieved by inserting RF chokes (inductors) in series foreach of the two leads that connects battery 302 to the PCB or any otherRF ground components, and may also include all additional control andmonitoring connections with the battery. The RF choking may beimplemented with ferrite beads that have high impedance at antennaoperating frequency range, for example, 2.402 GHz to 2.480 GHz, ornarrow band choking with inductors may be selected so that each of theinductors exhibits self-resonance at the mid-band of operationalfrequency, for example, 2.44 GHz. As one of ordinary skill in the artwould appreciate, self-resonance occurs because of capacitance definedby inductor, size, physical construction and type of materials used.Because the impedance of an inductor is very high at self-resonance,battery 302 electrically floats at the operational frequency, thusameliorating the effect of battery 302 upon the performance of antenna301.

The distance between antenna 301 and battery 302 is an importantconsideration. Increasing the distance to battery 302 may result inantenna current cancelation due to wire shape. If this occurs, theperformance of antenna 301 is adversely affected. On the other hand, itthe distance is too small, the electrical characteristics of antenna 301are adversely changed by battery 302.

The distance between antenna 301 and the PCB is also an importantconsideration. Generally, the antenna efficiency increases with thedistance. In the embodiment shown in FIG. 3, wire antenna 301 is locatedwithin housing 305. It is desirable to have a thin profile; thus thisdistance is small so that antenna 301 can be located within the housing.If the distance is too small, the efficiency of antenna 301 is adverselyaffected. In order to increase this distance, the diameter of the wirecan be reduced. However, the smaller the wire diameter, the smaller theantenna bandwidth. Thus, there is a tradeoff between the antennabandwidth and the antenna efficiency, where the wire diameter isselected based on the distance between wire antenna 301 and the PCB.

Based on experimentation and simulations, a tradeoff between the antennaefficiency and the antenna bandwidth is obtained. For example, with theembodiment shown in FIG. 3, the wire diameter of antenna 301 isapproximately 0.75 mm and the distance from the bottom of the wire tothe PCB is approximately 3.0 mm (corresponding to a distance to diameterratio of 4.0).

As discussed above, antenna 301 is advantageous with respect totraditional approaches. For example, the form factor of antenna 301minimizes antenna detuning caused by user interactions with wirelessearphones 101. In addition, the antenna wire shape, diameter, anddistance of wire antenna 301 from the PCB may be optimized for the besttradeoff between antenna bandwidth and radiated efficiency.

FIG. 4 shows cross sectional view 400 of wire antenna 301 incorporatedin wireless earphone 101 in accordance with an aspect of theembodiments. As shown in FIG. 4, distance 451 (the distance from thebottom of the wire of antenna 301 to PCB 401) is limited by the thinprofile of housing 402. Moreover, as wire diameter 452 increases,distance 451 decreases.

As distance 451 decreases (where antenna 301 is brought closer to theground plane), the antenna efficiency decreases. As wire diameter 452increases, the antenna bandwidth increases. Wire diameter 451 isselected (optimized) for the best tradeoff between the antenna bandwidthand the radiated efficiency, which are important to the desiredperformance of wireless earphones 101.

One of ordinary skill in the art will appreciate that engineeringjudgment may be exercised when selecting distance 451 and wire diameter452. Alternatively, a desired performance metric may be maximized. Forexample, a performance metric may be defined as:

Performance_Metric=W ₁*Bandwidth+W ₂*Efficiency  (EQ. 1)

where the antenna bandwidth and the antenna efficiency are weighted byW₁ and W₂, respectively.

FIG. 5 shows view 500 of wireless earphone 101 in accordance with anaspect of the embodiments. Battery 302 is often a major cause forantenna performance degradation, for example, when antenna 301 is closeto battery 302, the antenna radiation is deteriorated. To mitigate thiseffect, antenna 301 curves away from battery 302 along housing 402.

FIG. 6 shows wire antenna 301 mounted to PCB 401 at through-hole 601 inaccordance with an aspect of the embodiments. Traditional approachesoften use a pogo pin compressible connector connected between an antennaand a PCB, causing manufacturing reliability problems.

With some embodiments, antenna 301 is soldered to first and second padson the top and the bottom, respectively, of multi-layer PCB 401. With isapproach, a direct connection is established with through-hole 601.Because of the large relative size of antenna 301 with respect to thePCB foil thickness, large and potentially destructive physical forcesmay occur between antenna 301 and the PCB connections. To address thispossible condition, the first and second pads are large with respect totraditional approaches Because PCB 401 typically has thin foils andantenna 301 is large with respect to PCB 401, the first and second pads(where the first pad is shown as pad 602 and the second pad is notexplicitly shown) are relatively large to provide mechanical stabilityand robustness. While this approach is reliable with respect totraditional approaches, it provides a low-cost direct connection. Thisapproach circumvents the need for other more expensive and less reliabletraditional approaches such as springs, pogo pins, and so forth.

FIG. 7 shows a PCB layer specific VIA PCB stack-up geometry providingpartial impedance matching to wire antenna 301 of wireless earphone 101in accordance with an aspect of the embodiments. As previouslydiscussed, an end of antenna 301 is inserted into through-hole 601 andelectrically attached (for example, soldered) to multi-layer PCB 401.

As shown with the embodiment shown in FIG. 7, multi-layer PCB 401comprises eight PCB layers 701-708, where the top layer is designated atlayer 8, the bottom layer is designated as layer 1, and the inner PCBlayers are designated as layers 2-7. However, embodiments may support adifferent number of PCB layers. Adjacent layers are separated byspecified distances. For example, layer 8 and layer 7 are separated bydistance 751 and layer 7 and layer 6 are separated by distance 752.

The embodiment shown in FIG. 7 provides a reliable and low-cost directantenna connection as well as a PCB specific RF VIA geometry. As will bediscussed, the resulting electrical characteristics of the geometryprovides the required RF signal transition and partial impedancematching while eliminating the need for other commonly used and lessdesirable connection types such as pogo pins.

Electrical interaction between antenna 301 and each PCB layer 701-708contributes partial impedance matching of antenna 301 to transmissionline 202 (not explicitly shown in FIG. 7). For example, the distancebetween a corresponding pad and the conductive foil at each PCB layer(corresponding to anti-pad or anti-via) provides an impedancecontribution that results in the partial impedance value. As will beappreciated by one of ordinary skill in the art, the correspondingelectrical effects may be determined by electrical analysis, computermodeling, and/or simulations.

Once the partial impedance matching created by the multi-layer geometryis determined, a shunt capacitor may be included to fine-tune theimpedance matching of transmission line 202 to antenna 301. One ofordinary skill in the art will appreciate that impedance matching usingdistributed electrical characteristics of PCB 401 is preferable withrespect to impedance matching only with discrete electrical componentsbecause the antenna efficiency is improved.

FIG. 8 shows wire antenna 301 positioned by antenna holder 801 of awireless earphone in accordance with an aspect of the embodiments. Wireholder 801 enables for precise and consistent antenna mounting ofantenna 301 in earphone housing 305 (shown in FIG. 3 but not explicitlyshown in FIG. 8).

Antenna holder 801 may provide advantages with respect to traditionalapproaches. For example, the antenna radiation efficiency may beimproved by reducing dielectric losses. Dielectric material may beselectively removed from holder 801. For example, hole 802 may beintroduced while maintaining mechanical integrity of holder 801. Inaddition, holder 801 enables for the precise placement and manufacturingconsistency that is important to the improved performance of antenna301. For example, holder 801 helps to reduce manufacturingprocess-related resonance frequency variance.

FIG. 9 shows microstrip (transmission line) 202 located on a multi-layerPCB of wireless earphone 101 in accordance with an aspect of theembodiments. As previously discussed, microstrip 202 electricallyconnects a radio device (for example, a surface mounted transceiverchip) to wire antenna 301 (not explicitly shown in FIG. 9).

With some embodiments, PCB 401, as shown in FIG. 7, utilizeshigh-density interconnects (HDI) technology, where the spacing betweenlayers is very small (for example, 3 to 4 mils). This results in tracesbeing very narrow, where the component pads are a lot bigger than thewidth of 50 Ohms microstrip traces. With traditional approaches,transitions in the impedance caused by the pads are ignored.

Referring to FIG. 9, section 901 of microstrip 202 is typically designedto match to the impedance of the radio device (typically 50 ohms).However, because the corresponding ground plane is located at layer 7 ofthe multi-layer PCB (where the separation 751, as shown in FIG. 7, issmall—typically several mils), the width of section 901 is quite smallto obtain the 50 ohm impedance match.

Moreover, in order to mount electrical components along microstrip 202(for example, a filtering surface mounted device (SMD)), mounting pads(for example pad 902) are formed along microstrip 202. However, eventhough the SMD's are small, they are wide when compared to the width ofsection 901. (This comparison is shown in FIG. 10.) This change in widthmay disrupt the characteristic impedance of microstrip 202 andconsequently introduce RF signal insertion losses, impedance mismatch,and lower radiated power by the antenna element.

In order to mitigate the impedance change, embodiments may utilizecutouts 903 and 904 at layer 7 so that the ground plane is moved fromlayer 7 to layer 6. Consequently, the separation of the ground plane forportions of mounting pad 902 is increased from distance 751 to distance751+distance 752+distance through additional PCB layers if necessary (asshown in FIG. 7). The cutouts 903 and 904 are specifically optimizedrelative to selected RF ground layer and to take into consideration PCBlayout stackup and the dielectric constant

FIG. 10 shows a portion of a microstrip 202, as shown in FIG. 9, inaccordance with an aspect of the embodiments. Microstrip 202 is a typeof transmission line, where the characteristic impedance is related tothe W/D, W is the width of the microstrip, and D is the distance to theground plane.

If D were the same along sections 901 and 902 (where sections 901 and902 have widths 1001 and 1002, respectively) and section 901 has acharacteristic impedance of 50 ohms (for example, where the ground planeis located at layer 7), then the characteristic impedance of section 902could be significantly different from 50 ohms. Consequently, optimizedgeometry and size cutouts at layer 7 would properly reference the groundplane to layer 6 or layers below through additional cutouts

Referring to the embodiment shown in FIG. 9, computer simulations andexperimentation estimate a reflection loss of −18 dB and an insertionloss of −0.2 dB with cutouts. However, for the same embodiment butwithout cutouts, the reflection loss is −11 dB and an insertion loss of0.5 dB. Based on the above results, the performance improvement providedby the cutouts is significant.

FIG. 11 shows process 1100 for implementing wireless earphone 101 inaccordance with an aspect of the embodiments.

At block 1101, the wire diameter of wire antenna 301 is determined.Because the distance of antenna 301 to the ground plane (as provided byPCB 401) is restricted by the thin profile of earphone 101, the wirediameter may significantly affect the distance. The diameter may bedetermined based on a performance metric (for example, defined by EQ.1). When an acceptable antenna bandwidth and efficiency tradeoff isobtained, as determined at block 1102 and where the antenna shape andwire diameter is often driven by an Industrial Design (ID) form factor,process 1100 proceeds with the assembling configuration of antenna 301in the housing of wireless earphone 101.

A first end of antenna 301 is inserted into through-hole 601 of PCB 401at block 1103 and electrically connected (for example, soldered) to topand bottom pads at block 1104.

Because antenna 301 must fit within the thin profile of the housing,antenna 301 is bent to transition to a horizontal orientation and isshaped to curve around the housing (and typically away from a battery)at block 1105.

In order to avoid close proximity to the battery, a sharp bend isintroduced at the second end of antenna at block 1106. However,consideration must be accorded so that the bend does not cause currentcancelations with other portions of antenna 301, thus degrading theperformance of antenna 301.

At block 1107, a constant impedance is maintained (with respect totraditional approaches) along microstrip 202 that connects radio device201 and antenna 301 by forming cutouts along microstrip 202 and underassociated components.

At block 1108, the VIA PCB stack-up geometry is determined to obtainpartial impedance matching with antenna 301 and microstrip 202. Furtherimpedance matching is obtained using a shunt capacitor that is connectedto the antenna port.

FIG. 12 shows wireless earphone 1201 situated in user's ear 1202.Referring back to FIG. 1, rather than being held in place by an externalattachment (for example, a hook) at or around the ear, wireless earphoneis held in place by an eartip (not explicitly shown) inserted into theuser's ear canal.

FIG. 13 shows wire antenna 301 positioned by antenna holder 1301 inaccordance with an aspect of the embodiments. Antenna holder 1301 issimilar to antenna holder 801 as shown in FIG. 8. By keeping thedimensions of hole 1302 the same as those of hole 302 while removingmaterial around periphery 1303 of holder 1301, the resulting electricalcharacteristics of antenna 301 are essentially the same as antennaholder 801 (within a predetermined difference).

As previously discussed, the form factor of an antenna may reduceantenna detuning caused by user interactions. FIG. 15 further showaspects of the disclosure in which the effects of user interaction uponantenna detuning are reduced. As shown in FIG. 14, wireless earphone1401 is inserted into ear 1402 of a user. The user interacts withearphones through button 1503 as shown in FIG. 15. The effects of userinteraction may be reduced in several ways. First, the unobstructed areaaround the antenna of wireless earphones 1401 significantly reducesantenna detuning. Second, button 1503 is positioned so that fingers ofthe user stay away from the antenna region when pressing button 1503during normal user interaction. Third, the counterforce at the bottom ofthe unit is required while pressing the top UI button for the earphonesto stay comfortably in user ear. The design allows for natural thumbplacement during this interaction such that it does not significantlydetune the antenna.

Antenna detuning may be characterized by a predetermined frequencydeviation that is based on a percentage from the intended centerfrequency of antenna 301 (as shown in FIG. 3). For example, thepredetermined frequency deviation may be ½ percent, 1 percent, 2percent, or 5 percent (corresponding to 12 MHz, 24 MHz, 48 MHz, 120 MHz,respectively) from the intended center frequency of 2.4 GHz.

In order to be within a predetermined frequency deviation, button 1503is exposed through the housing and configured to provide interaction ofa user with the wireless earphone, where button 1503 is positioned sothat the user's fingers are separated from antenna 301 greater than apredetermined distance when the user presses the user input deviceduring normal user interaction. For example, button 1503 may be locatedat least 0.5 inches, 0.2 inches, or 0.1 inches from antenna 301 in orderto obtain varying degrees of antenna detuning.

Embodiments may support other types of user interface devices other thanbutton 1503. For example, a user interface device may comprise acapacitive sensor that is responsive to a user's finger touching or inclose proximity to the sensor.

Antenna 301 may be mounted on PCB 401 (as shown in FIG. 4) within anunobstructed area of the PCB that is void of relatively large, metallicelectrical components that may detune antenna 301. For example, arelatively large component may have one or dimensions that is greaterthan 0.01λ or 0.02λ or 0.05λ, where λ is the operating wavelength. Asshown in FIG. 3, antenna 301 is mounted away from battery 302.

As shown in FIG. 15, button 1503 is exposed through the top of thehousing. However, button may be exposed through different positions ofthe housing, for example, through one of the sides or the bottom.

Aspects of the disclosure have been described in terms of illustrativeembodiments thereof. Numerous other embodiments, modifications, andvariations within the scope and spirit of the appended claims will occurto persons of ordinary skill in the art from a review of thisdisclosure. For example, one of ordinary skill in the art willappreciate that the steps illustrated in the illustrative figures may beperformed in other than the recited order, and that one or more stepsillustrated may be optional in accordance with aspects of thedisclosure.

Exemplary Clauses

1. A wireless earphone for receiving audio content over a wirelesscommunication channel at a desired frequency spectrum, the wirelessearphone comprising:

a multi-layer printed circuit board (PCB);

an antenna assembly comprising a wire antenna, wherein the wire antennahas a wire length compatible with the desired frequency spectrum,comprises a first end, and is characterized by an antenna radiationresistance and wherein the first end is inserted through a through-holeof the multi-layer PCB; and

an impedance matching interface utilizing an electrical interactionbetween the first end of the wire antenna and at least one PCB layer ofthe multi-layer PCB, wherein the wireless earphone is at least partiallymatched to an antenna impedance.

2. The wireless earphone of clause 1, wherein the first end of the wireantenna is electrically connected to a top pad of the through-hole and abottom pad of the through-hole.3. The wireless earphone of clause 1, wherein the impedance matchinginterface comprises a shunt capacitor and wherein the wireless earphoneis further matched to the antenna impedance by the shunt capacitor.4. The wireless earphone of clause 1 comprising a housing, wherein asection of the wire antenna is approximately parallel to the multi-layerPCB and is specifically shaped around a portion of the housing.5. The wireless earphone of clause 4, wherein the wire antenna includesa bend to maintain a minimum distance of a second end of the wireantenna from at least one metallic component of the wireless earphone.6. The wireless earphone of clause 5, wherein the antenna assemblyfurther comprises an antenna holder and wherein the antenna holderattaches to the section of the wire antenna to support the wire antennaa desired distance from the multi-layer PCB.7. The wireless earphone of clause 6, wherein the antenna holderincludes a hole to reduce an amount of dielectric material, thus tominimize dielectric losses and antenna dielectric loading.8. The wireless earphone of clause 1 further comprising:

a radio device; and

a transmission line configured to electrically connect the radio deviceto the impedance matching interface, wherein the transmission lineincludes an electrical component and an associated cutout of a groundplane and wherein the associated cutout is located below the electricalcomponent on an adjacent layer or layers below adjacent layer of themulti-layer PCB.

9. The wireless earphone of clause 1, wherein the desired frequencyspectrum spans 2.40 GHz to 2.4835 GHz.10. The wireless earphone of clause 1, wherein the wire antenna ischaracterized by a distance-diameter ratio of approximately four,wherein the wire antenna comprises an electrical wire having a diameterand has a spacing distance between a bottom of the electrical wire tothe multi-layer PCB.11. The wireless earphone of clause 10, wherein the electrical wire hasthe diameter of approximately 0.8 mm and the spacing distance ofapproximately 3 mm.12. The wireless earphone of clause 1, wherein each internal PCB layerof the multi-layer PCB has a specific opening to provide a desiredcontribution to the distributed impedance matching.13. The wireless earphone of clause 2, wherein the top pad and thebottom pad are aligned to the through-hole and wherein the wire antennais electrically connected to the top and bottom pads by solderconnections.14. The wireless earphone of clause 13, wherein a first size of the toppad and a second size of the bottom pad provide sufficient mechanicalstrength for supporting the wire antenna.15. The wireless earphone of clause 1 further comprising:

a battery configured to provide electrical power to the wirelessearphone through a first lead and a second lead;

a first ferrite bead electrically connected between the battery and thefirst lead; and

a second ferrite bead electrically connected between the battery and thesecond lead,

wherein the first ferrite bead and the second ferrite bead are selectedto exhibit high impedance in the desired frequency spectrum and whereinthe battery electrically floats relative to RF ground at the operationalfrequency.

16. The wireless earphone of clause 1 further comprising:

a battery configured to provide electrical power to the wirelessearphone through a first lead and a second lead;

a first inductor electrically connected between the battery and thefirst lead; and

a second inductor electrically connected between the battery and thesecond lead,

wherein the first inductor and the second inductor exhibit aself-resonance at an operational frequency in the desired frequencyspectrum and wherein the battery electrically floats relative to RFground at the operational frequency.

17. The wireless earphone of clause 15, further comprising:

additional ferrite beads electrically connected between the battery andRF ground components such as PCB, e.g. battery control and monitoringlines,

wherein the additional ferrite beads are selected to exhibit highimpedance in the desired frequency spectrum.

18. The wireless earphone of clause 16, further comprising:

additional inductors electrically connected between the battery and RFground components such as PCB, e.g. battery control and monitoringlines,

wherein the additional inductors are selected to exhibit high impedancein the desired frequency spectrum.

19. The wireless earphone of clause 15, wherein the battery includesadditional leads.20. The wireless earphone of clause 16, wherein the battery includesadditional leads.21. A method for supporting wireless communication at a desiredfrequency spectrum for a wireless earphone, the method comprising:

determining a wire diameter of a wire antenna and an antenna distance toPCB ground plane based on a tradeoff between an antenna bandwidth and aradiation efficiency of the wire antenna;

inserting a first end of the wire antenna through a through-hole of amulti-layer printed circuit board (PCB); and

providing at least a partial impedance matching of the wireless earphonewith the wire antenna with a PCB layer specific VIA PCB stack-upgeometry.

22. The method of clause 21 further comprising:

bending the wire antenna so that a section of the wire antenna isapproximately parallel to the multi-layer PCB; and

shaping the wire antenna around a portion of a housing; and

bending at a second end of the wire antenna to maintain a minimumdistance of the second end from at least one metallic component of thewireless earphone.

23. The method of clause 22 further comprising:

establish an approximate constant impedance along a transmission lineconnecting a radio device to the wire antenna, the maintaining furthercomprising:

-   -   cutting out a portion of a ground plane below an electrical        component along the transmission line, wherein the portion is        located below the electrical component on an adjacent PCB layer        or layers below adjacent layer of the multi-layer PCB.        24. The method of clause 21 further comprising:

electrically connecting the first end of the wire antenna to a top PCBlayer and a bottom PCB layer, respectively.

25. The method of clause 21 further comprising:

inserting a shunt capacitance to a feed point of the wire antenna toprovide a desired impedance matching of the wireless earphone with thewire antenna in conjunction with the partial impedance matching.

26. A wireless earphone for supporting a wireless communication channelat a desired frequency spectrum, the wireless earphone comprising:

a radio circuit configured to extract audio content from a wirelesssignal received over the wireless communication channel;

a multi-layer printed circuit board (PCB);

a wire antenna, wherein the wire antenna has a wire length compatiblewith the desired frequency spectrum, the wire antenna has a first endinserted through a through-hole of the multi-layer PCB, and wire antennais characterized by an antenna impedance; and

a transmission line electrically connecting the radio circuit with thewire antenna and having an approximate constant impedance along thetransmission line, wherein the transmission line includes an electricalcomponent and an associated cutout of a ground plane and wherein theassociated cutout is located below the electrical component on anadjacent PCB layer of the multi-layer PCB.

27. The wireless earphone of clause 26, further comprising:

an impedance matching interface, wherein the wireless earphone is atleast partially matched to the antenna impedance by an electricalinteraction between the first end of the wire antenna and at least onePCB layer.

28. The wireless earphone of clause 26 comprising a housing, wherein asection of the wire antenna is approximately parallel to the multi-layerPCB and is shaped around a portion of the housing.29. The wireless earphone of clause 28, wherein the wire antennaincludes a bend to maintain a minimum distance of a second end of thewire antenna from at least one metallic component of the wirelessearphone.30. The wireless earphone of clause 26, wherein the first end iselectrically connected to a top pad of the through-hole and a bottom padof the through-hole.31. A wireless earphone for receiving audio content over a wirelesscommunication channel at a desired frequency spectrum, the wirelessearphone comprising:

a housing;

a printed circuit board (PCB) located within the housing;

an antenna assembly comprising a wire antenna, wherein the wire antennahas a wire length compatible with the desired frequency spectrum andwherein the antenna assembly is electrically mounted on the PCB withinan unobstructed area; and

a user input device configured to provide interaction of a user with thewireless earphone, wherein the user input device is positioned so thatfingers of the user are separated from the wire antenna greater than apredetermined distance when the user presses the user input deviceduring normal user interaction,

wherein antenna detuning of the antenna assembly by the normal userinteraction is within a predetermined frequency deviation.

32. The wireless earphone of clause 31 further comprising a surfaceregion on the housing configured to accommodate thumb placement of theuser, wherein a resulting force applied by a thumb of the usercounteracts the pressing of the user input device by the user,33. The wireless earphone of clause 31 further comprising a batteryconfigured to provide electrical power to the wireless earphone, whereinthe wire antenna is characterized by a first bend at an end of the wireantenna to maintain a minimum distance from a battery of the wirelessearphone and the fingers of the user during the normal user interaction.34. The wireless earphone of clause 33, wherein the wire antenna ischaracterized by a second bend so that the wire antenna is parallel withthe PCB.35. The wireless earphone of clause 34, wherein the wire antenna ischaracterized by a third bend to accommodate a curved portion of thehousing.36. The wireless earphone of clause 35, wherein the antenna assemblycomprises an antenna holder and wherein the antenna holder attaches tothe wire antenna at the end and the third bend and supports the wireantenna at a desired distance from the PCB.37. The wireless earphone of clause 31, wherein the user input devicecomprises a button.38. A wireless earphone for receiving audio content over a wirelesscommunication channel at a desired frequency spectrum, the wirelessearphone comprising:

a housing;

a printed circuit board (PCB) located within the housing;

an antenna assembly comprising a wire antenna, wherein the wire antennahas a wire length required for antenna resonance at the desiredfrequency spectrum and wherein the antenna assembly is electricallymounted on the PCB within an unobstructed area of the PCB; and

a user input device configured to provide interaction of a user with thewireless earphone, wherein the user input device is positioned so thatfingers of the user are separated from the wire antenna greater than apredetermined distance when the user presses the user input deviceduring normal user interaction,

wherein antenna detuning of the antenna assembly by the normal userinteraction is within a predetermined frequency deviation.

What is claimed is:
 1. A wireless earphone for receiving audio contentover a wireless communication channel at a desired frequency spectrum,the wireless earphone comprising: a multi-layer printed circuit board(PCB); an antenna assembly comprising a wire antenna, wherein the wireantenna has a wire length compatible with the desired frequencyspectrum, comprises a first end, and is characterized by an antennaradiation resistance and wherein the first end is inserted through athrough-hole of the multi-layer PCB; and an impedance matching interfaceutilizing an electrical interaction between the first end of the wireantenna and at least one PCB layer of the multi-layer PCB, wherein thewireless earphone is at least partially matched to an antenna impedance.2. The wireless earphone of claim 1, wherein the first end of the wireantenna is electrically connected to a top pad of the through-hole and abottom pad of the through-hole.
 3. The wireless earphone of claim 1,wherein the impedance matching interface comprises a shunt capacitor andwherein the wireless earphone is further matched to the antennaimpedance by the shunt capacitor.
 4. The wireless earphone of claim 1comprising a housing, wherein a section of the wire antenna isapproximately parallel to the multi-layer PCB and is specifically shapedaround a portion of the housing.
 5. The wireless earphone of claim 4,wherein the wire antenna includes a bend to maintain a minimum distanceof a second end of the wire antenna from at least one metallic componentof the wireless earphone.
 6. The wireless earphone of claim 5, whereinthe antenna assembly further comprises an antenna holder and wherein theantenna holder attaches to the section of the wire antenna to supportthe wire antenna a desired distance from the multi-layer PCB.
 7. Thewireless earphone of claim 6, wherein the antenna holder includes a holeto reduce an amount of dielectric material, thus to minimize dielectriclosses and antenna dielectric loading.
 8. The wireless earphone of claim1 further comprising: a radio device; and a transmission line configuredto electrically connect the radio device to the impedance matchinginterface, wherein the transmission line includes an electricalcomponent and an associated cutout of a ground plane and wherein theassociated cutout is located below the electrical component on anadjacent layer or layers below adjacent layer of the multi-layer PCB. 9.The wireless earphone of claim 1, wherein the desired frequency spectrumspans 2.40 GHz to 2.4835 GHz.
 10. The wireless earphone of claim 1,wherein the wire antenna is characterized by a distance-diameter ratioof approximately four, wherein the wire antenna comprises an electricalwire having a diameter and has a spacing distance between a bottom ofthe electrical wire to the multi-layer PCB.
 11. The wireless earphone ofclaim 10, wherein the electrical wire has the diameter of approximately0.8 mm and the spacing distance of approximately 3 mm.
 12. The wirelessearphone of claim 1, wherein each internal PCB layer of the multi-layerPCB has a specific opening to provide a desired contribution to thedistributed impedance matching.
 13. The wireless earphone of claim 2,wherein the top pad and the bottom pad are aligned to the through-holeand wherein the wire antenna is electrically connected to the top andbottom pads by solder connections.
 14. The wireless earphone of claim13, wherein a first size of the top pad and a second size of the bottompad provide sufficient mechanical strength for supporting the wireantenna.
 15. The wireless earphone of claim 1 further comprising: abattery configured to provide electrical power to the wireless earphonethrough a first lead and a second lead; a first ferrite beadelectrically connected between the battery and the first lead; and asecond ferrite bead electrically connected between the battery and thesecond lead, wherein the first ferrite bead and the second ferrite beadare selected to exhibit high impedance in the desired frequency spectrumand wherein the battery electrically floats relative to RF ground at anoperational frequency.
 16. The wireless earphone of claim 1 furthercomprising: a battery configured to provide electrical power to thewireless earphone through a first lead and a second lead; a firstinductor electrically connected between the battery and the first lead;and a second inductor electrically connected between the battery and thesecond lead, wherein the first inductor and the second inductor exhibita self-resonance at an operational frequency in the desired frequencyspectrum and wherein the battery electrically floats relative to RFground at the operational frequency.
 17. The wireless earphone of claim15, further comprising: additional ferrite beads electrically connectedbetween the battery and RF ground components, wherein the additionalferrite beads are selected to exhibit high impedance in the desiredfrequency spectrum.
 18. The wireless earphone of claim 16, furthercomprising: additional inductors electrically connected between thebattery and RF ground components, wherein the additional inductors areselected to exhibit high impedance in the desired frequency spectrum.19. The wireless earphone of claim 15, wherein the battery includesadditional leads.
 20. The wireless earphone of claim 16, wherein thebattery includes additional leads.
 21. A wireless earphone forsupporting a wireless communication channel at a desired frequencyspectrum, the wireless earphone comprising: a radio circuit configuredto extract audio content from a wireless signal received over thewireless communication channel; a multi-layer printed circuit board(PCB); a wire antenna, wherein the wire antenna has a wire lengthcompatible with the desired frequency spectrum, the wire antenna has afirst end inserted through a through-hole of the multi-layer PCB, andwire antenna is characterized by an antenna impedance; and atransmission line electrically connecting the radio circuit with thewire antenna and having an approximate constant impedance along thetransmission line, wherein the transmission line includes an electricalcomponent and an associated cutout of a ground plane and wherein theassociated cutout is located below the electrical component on anadjacent PCB layer of the multi-layer PCB.
 22. The wireless earphone ofclaim 21, further comprising: an impedance matching interface, whereinthe wireless earphone is at least partially matched to the antennaimpedance by an electrical interaction between the first end of the wireantenna and at least one PCB layer.
 23. The wireless earphone of claim21 comprising a housing, wherein a section of the wire antenna isapproximately parallel to the multi-layer PCB and is shaped around aportion of the housing.
 24. The wireless earphone of claim 23, whereinthe wire antenna includes a bend to maintain a minimum distance of asecond end of the wire antenna from at least one metallic component ofthe wireless earphone.
 25. The wireless earphone of claim 21, whereinthe first end is electrically connected to a top pad of the through-holeand a bottom pad of the through-hole.
 26. A wireless earphone forreceiving audio content over a wireless communication channel at adesired frequency spectrum, the wireless earphone comprising: a housing;a printed circuit board (PCB) located within the housing; an antennaassembly comprising a wire antenna, wherein the wire antenna has a wirelength compatible with the desired frequency spectrum and wherein theantenna assembly is electrically mounted on the PCB within anunobstructed area; and a user input device configured to provideinteraction of a user with the wireless earphone, wherein the user inputdevice is positioned so that fingers of the user are separated from thewire antenna greater than a predetermined distance when the user pressesthe user input device during normal user interaction, wherein antennadetuning of the antenna assembly by the normal user interaction iswithin a predetermined frequency deviation.
 27. The wireless earphone ofclaim 26 further comprising a surface region on the housing configuredto accommodate thumb placement of the user, wherein a resulting forceapplied by a thumb of the user counteracts the pressing of the userinput device by the user,
 28. The wireless earphone of claim 26 furthercomprising a battery configured to provide electrical power to thewireless earphone, wherein the wire antenna is characterized by a firstbend at an end of the wire antenna to maintain a minimum distance from abattery of the wireless earphone and the fingers of the user during thenormal user interaction.
 29. The wireless earphone of claim 28, whereinthe wire antenna is characterized by a second bend so that the wireantenna is parallel with the PCB.
 30. The wireless earphone of claim 29,wherein the wire antenna is characterized by a third bend to accommodatea curved portion of the housing.
 31. The wireless earphone of claim 30,wherein the antenna assembly comprises an antenna holder and wherein theantenna holder attaches to the wire antenna at the end and the thirdbend and supports the wire antenna at a desired distance from the PCB.32. The wireless earphone of claim 26, wherein the user input devicecomprises a button.